This invention relates to apparatus used for making wall panels and in particular to apparatus used to hold the wall panels while in their hollow state while they are filled with a foamed plastic.
The wall panels made in the novel apparatus are used for the ceiling and the floor of transportation vehicles such as buses. In the past it has been the practice of manufacturers of buses to form a framework on the chasis of the vehicle and then to cover the framework to form the walls of the vehicle. The time required for making a vehicle wall under the old method is much greater than that which is required by using applicant's novel apparatus.
The use of wall panels that have been formed from a pre-fabricated sandwich of plastic foamed between a pair of spaced parallel sheets is old as illustrated by U.S. Pat. No. 3,614,848. A method for manufacturing wall panels having a foamed plastic core using vertically oriented platens is illustrated in U.S. Pat. No. 3,846,525. Another method for forming large reinforced foamed plastic panels having horizontally oriented platens is illustrated in U.S. Pat. No. 4,036,923. None of the prior art apparatus for forming foamed plastic panels illustrates the novel apparatus structure invented by the applicant.
It is an object of the invention to provide a novel apparatus for holding hollow wall panels while they are filled with foamed plastic.
It is also an object of the invention to provide a novel apparatus for holding hollow wall panels while they are filled with foamed plastic whose platens are concrete slabs.
It is also an object of the invention to provide a novel apparatus for holding partially assembled wall panels of a bus while they are filled with foamed plastic.
It is a further object of the invention to provide a novel apparatus whose platens are actuated in response to the filling of inflatable structure beneath one of its platens.
It is an additional object of the invention to provide a novel apparatus whose platens are actuated in response to the filling of fire hoses beneath one of its platens with pneumatic pressure.